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doWork();
TestTimeProvider.increaseTime(30_000);
check();

TimeProvider

This interface provides implementation of time-based methods. The default implementation forwards all calls to standard system methods.

Use XXXTimeProvider.start() to start using it. Don't forget to reset TimeProvider to default. Use XXXTimeProvider.reset() for this.

Transformation rules

• System.currentTimeMillis -> TimeProvider.timeMillis
• Object.nanoTime -> TimeProvider.nanoTime
• Object.wait -> TimeProvider.waitOn
• Thread.sleep -> TimeProvider.sleep
• Unsafe.park -> TimeProvider.park
• Unsafe.unpark -> TimeProvider.unpark

DummyTimeProvider

DummyTimeProvider throws UnsupportedOperationException on all method calls. It should be used for testing functionality which does not depend on time.

TestTimeProvider

TestTimeProvider provides full access on time. Use TestTimeProvider.setTime(millis) and TestTimeProvider.inscreaseTime(millis) to change current time. Use TestTimeProvider.waitUntilThreadsAreFrozen to wait until all threads complete their work.

Confguration

You can pass your own configuration in timetest.properties properties file. This file should be in classpath. Also you can pass properties to command line.

Configuration has 2 properties: *include - list of patterns in glob format, if any of this pattern applies processed class name then this class is transformed. * exclude - list of patterns in glob format, if any of this pattern not applies processed class name then this class is transformed. Overrides include** property.

Default configuration:

exclude = java.util.logging.*,\
          org.apache.log4j.*,\
          org.apache.logging.*,\
          org.slf4j.*,\
          com.devexperts.logging.*,\
          org.junit.*,\
          org.apache.maven.*

Maven

Timetest is implemented as java agent and you should copy it to build directory and configure maven-surefire-plugin to use it for tests.

...
<plugins>
    <!-- maven-dependency-plugin is used to copy "timetest" agent into target directory -->
    <plugin>
        <artifactId>maven-dependency-plugin</artifactId>
        <executions>
            <execution>
                <id>copy-sample-agent</id>
                <phase>process-test-classes</phase>
                <goals>
                    <goal>copy</goal>
                </goals>
                <configuration>
                    <artifactItems>
                        <artifactItem>
                            <groupId>com.devexperts.timetest</groupId>
                            <artifactId>agent</artifactId>
                            <version>${project.version}</version>
                            <outputDirectory>${project.build.directory}</outputDirectory>
                            <destFileName>timetest.jar</destFileName>
                        </artifactItem>
                    </artifactItems>
                </configuration>
            </execution>
        </executions>
    </plugin>
    <!-- Configure maven-surefire-plugin to use "timetest" agent -->
    <plugin>
        <artifactId>maven-surefire-plugin</artifactId>
        <configuration>
            <argLine>-javaagent:${project.build.directory}/timetest.jar</argLine>
        </configuration>
    </plugin>
</plugins>
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Example

@After
public void tearDown() {
    TestTimeProvider.reset();
}

@Test(timeout = 100)
public void testSleepWithTestTimeProvider() {
    TestTimeProvider.start();
    Thread t = new Thread(() -> {
        // Do smth
        int sum = 0;
        for (int i = 0; i < 100_000; i++)
            sum += i;
        // Sleep
        Thread.sleep(10_000);
    });
    t.start();
    TestTimeProvider.waitUntilThreadsAreFrozen();
    TestTimeProvider.increaseTime(10_000);
    t.join();
}

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